Light detection systems have been widely used in autonomous driving and producing high-definition maps. For example, Light Detection and Ranging (LiDAR) systems measure distance to a target by illuminating the target with pulsed laser light and measuring the reflected pulses with a sensor. Differences in laser return times and wavelengths can then be used to make digital three-dimensional (3-D) representations of the target. The laser light used for LiDAR scan may be ultraviolet, visible, or near infrared. Because a narrow laser beam as the incident light from the scanner can map physical features with very high resolution, a LiDAR system is particularly suitable for high-definition map surveys.
However, a wide scan angle is typically used by LiDAR to capture the scene. Accordingly, the detector of a typical LiDAR system usually includes a single lens-receiver unit having a wide field of view (FOV) to ensure that the returned light can be well captured. In that case, the optical gain, i.e. the amount of light the system can admit, is limited, thereby limiting the signal-to-noise ratio (SNR) and system performance. Moreover, traditional detectors allow more interferences to be received with a single wide-angle lens, which can further reduce SNR and the scan resolution.
Embodiments of the disclosure address the above problems by an improved system for light detection having multiple lens-receiver units.